Pozelimab is a recombinant fully human monoclonal antibody and a specialized biological active pharmaceutical ingredient (API) designed to target the terminal complement protein C5. The substance is also known as pozelimab-bbfg and was developed under the code REGN3918. Its CAS Number is 2096328-94-6, FDA UNII is 0JJ21K6L2I, and it is classified as a human immunoglobulin G4-kappa (IgG4κ) monoclonal antibody. FDA records identify an estimated molecular weight of approximately 145,000 Da (145 kDa).
Pozelimab works by binding to complement protein C5 and preventing its cleavage into C5a and C5b. This inhibits terminal complement activation and prevents formation of the membrane-attack complex (C5b-C9), which is responsible for complement-mediated cell lysis.
Pozelimab-bbfg is the active ingredient of VEOPOZ, an FDA-approved biological product. VEOPOZ is indicated for the treatment of CD55-deficient protein-losing enteropathy (PLE), also known as CHAPLE disease, in adults and pediatric patients one year of age and older. The FDA approval represents an important application of targeted complement inhibition for this rare disorder.
Unlike conventional small-molecule APIs, Pozelimab is a large recombinant protein. It is produced using recombinant DNA technology in Chinese hamster ovary (CHO) cell suspension culture. The antibody belongs to the IgG4 class and incorporates an Fc-region serine-to-proline substitution at position 228, which helps stabilize the disulfide bonds between the two heavy chains.
FDA GSRS provides the estimated molecular formula C6418H9886N1692O2026S42 and an estimated average molecular weight of 145,000 Da. Because monoclonal antibodies are glycosylated, heterogeneous biological molecules, their molecular weight should not be treated in the same way as the exact molecular weight of a conventional synthetic small molecule.
Pozelimab API is primarily relevant to complement-mediated and rare-disease therapeutic development, including:
European regulatory development has also included pediatric investigation plans involving pozelimab for other complement-related conditions, including paroxysmal nocturnal haemoglobinuria and generalized juvenile myasthenia gravis. These regulatory-development activities should not be interpreted as additional approved indications unless specifically authorized.
Pozelimab requires a biological drug-substance quality-control strategy rather than a conventional small-molecule API specification. Critical quality attributes for a monoclonal antibody typically include identity, purity, aggregation, charge variants, glycosylation, potency, host-cell protein, host-cell DNA, residual process components and microbial safety.
For Pozelimab specifically, FDA regulatory documentation identifies the material as a recombinant IgG4 antibody produced in CHO cells and describes the final drug product as a clear to slightly opalescent, colorless to pale yellow solution.
Because public FDA documentation does not provide a complete numerical release specification for the Pozelimab drug substance, unsupported values such as “99% purity,” “98–102% assay,” or conventional HPLC impurity limits should not be presented as official Pozelimab API specifications.
A Pozelimab API manufacturer in India requires biologics manufacturing capabilities appropriate for recombinant monoclonal antibodies. Manufacturing controls should cover cell-culture production, purification, viral safety, protein characterization, aseptic processing where applicable and preservation of the antibody's structural and functional integrity.
The production platform is based on recombinant DNA technology using CHO cells. Consequently, quality systems should address cell-substrate controls, upstream processing, downstream purification, viral clearance, protein aggregation, product-related variants and process-related impurities.
Analytical characterization should be designed around the molecule's critical quality attributes rather than forcing small-molecule tests into the API specification.
The approved VEOPOZ drug product is supplied as a sterile, preservative-free solution in a single-dose glass vial containing 400 mg in 2 mL, corresponding to 200 mg/mL. The drug product has a reported pH of 5.8. These values describe the finished drug product formulation, not a universal Pozelimab bulk drug-substance specification.
For bulk Pozelimab drug substance, packaging and storage should follow validated stability data and the applicable manufacturing specification. Protection from inappropriate temperature exposure, contamination, agitation and other conditions capable of affecting protein integrity is important for monoclonal-antibody materials.
Pozelimab biological API documentation may include:
Pozelimab is a highly specialized recombinant monoclonal antibody targeting complement C5. Its established mechanism, defined molecular identity, recombinant CHO-cell production platform and clinical application in CD55-deficient protein-losing enteropathy make it an important biological API for specialized pharmaceutical development.
For pharmaceutical organizations working with Pozelimab, quality evaluation should focus on biological identity, structural integrity, purity, aggregation, potency, process-related impurities and microbiological/viral safety rather than conventional small-molecule API parameters.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Water Content | NMT 0.5% |